Newcastle-under-Lyme is a market town in Staffordshire, and is the principal settlement in the Borough of Newcastle-under-Lyme. It is part of North Staffordshire.

The "Newcastle" part of the name derives from being the location of a new castle in the 12th century. The "Lyme" section could refer to the Lyme Brook or the extensive Forest of Lyme that covered the area with lime trees in the Middle Ages. The well-known Berlin street Unter den Linden is a cognate of 'under-Lyme'